L-Carnitine is a quaternary amine that promotes beta-oxidation of long-chain fatty acids by facilitating their transfer across the mitochondrial membrane. L-Carnitine has also been shown to promote oxidation of branched-chain amino acids and the utilization of acetyl-coenzyme A.
In mammalian species, L-Carnitine concentration in cardiac and skeletal muscle is much higher than in serum. In these tissues fatty acids are utilized as a major source of energy. Because of L-Carnitine's central role in transporting fatty acids to the site of oxidation, adequate levels of L-Carnitine are required for normal fatty acid and energy metabolism in mammalian hearts. This is evidenced by the restoration to normal of fatty acid oxidation in muscle homogenates of certain L-Carnitine deficient patients. A relationship between deficient levels of myocardial L-Carnitine and cardiomyopathy has been observed in both hamsters and dogs. Restoration toward normal of such deficient L-Carnitine levels has been shown to result in improved myocardial function in both species.
In mammals, L-Carnitine is derived from the diet and from biosynthesis in the liver, and in some species, kidney and other tissues. Neither cardiac nor skeletal muscle is capable of synthesizing L-Carnitine, however. Thus, the L-Carnitine found in these tissues was either absorbed from the diet or biosynthesized endogenously by other tissues.
The present invention is for a method of preventing diet-induced carnitine deficiency in domesticated dogs and cats using a dietary supplement containing a prophylactic amount of L-Carnitine. The invention is useful in preventing L-Carnitine deficiencies which can lead to a multitude of conditions, including myopathic heart disease, ischemic heart disease, hyperlipidemia, ketosis, muscle weakness and premature aging.
Pets, particularly the carnivores, are at great risk for developing L-Carnitine deficiencies. As Table 1 indicates, dog and cat foods are extremely low in free L-Carnitine levels as compared with that found in raw ground beef. Most pets are maintained strictly on commercial pet food diets and are thus kept chronically deficient in L-Carnitine. Additionally, applicants' own investigations have found that renal reabsorption of L-Carnitine in dogs ranges from 40% to 95% with the average approximately 75% depending to some extent on diet. This is in marked contrast to the human which has a renal reabsorption approaching 100%. The less efficient renal reabsorption in dogs means that L-Carnitine is lost in the urine. This combined with a diet deficient in L-Carnitine results in a diet-induced carnitine deficiency.
TABLE 1 __________________________________________________________________________ LEVEL OF FREE L-CARNITINE IN PET FOODS FREE L-CARNITINE "WATER SOLUBLE FRACTION" SAMPLE IDENTIFICATION nanomoles/gram of product __________________________________________________________________________ GROUND BEEF 3000.0 ** SAMPLE TYPE: DRY DOG FOOD ALPO BEEF FLAVORED DINNER 5 LBS 214.2 CARNATION COME N GET IT 4 LBS 53.6 GAINES GRAVY TRAIN BEEF FLAVOR 5 LBS 89.4 KALKAN MEALTIME SMALL CRUNCHY BITS 5 LBS 105.9 KEN-L-RATION LOVE ME TENDER CHUNKS-BEEF 27.3 KEN-L-RATION KIBBLES 'N BITS 4 LBS 78.6 PETTS BRAND ALL NATURAL (HUBBARD) 4 LBS 167.7 PURINA DOG CHOW 5 LBS 161.0 PURINA CHUCKWAGON DOG CHOW 72.7 PURINA HI-PRO 5 LBS 93.2 PURINA BUTCHER'S BLEND BEEF, BACON, LIVER 106.3 PURINA FIT AND TRIM 4.5 LBS 103.9 PURINA PUPPY CHOW 5 LBS 136.0 NUTRO MAX PUPPY KIBBLE PUPPY FOOD 143.5 NUTRO MAX KIBBLE DOG FOOD 192.7 IAMS MINI CHUNKS 182.9 EUKANUBA (BY IAMS) 216.3 ** SAMPLE TYPE: SEMI-MOIST DOG FOOD GAINES BURGERS - BEEF 36 OZ 55.5 KEN-L-RATION SPECIAL CUTS 24 OZ 59.2 ** SAMPLE TYPE: CANNED DOG FOOD ALPO BEEF & LIVER DINNER 14 OZ 222.8 ALPO LAMB CHUNKS 89.2 CARNATION MIGHTY DOG BEEF 6.5 OZ 1799.1 CARNATION MIGHTY DOG TURKEY & GIBLETS 172.3 GAINES CYCLE 2 (ADULT) BEEF 14 OZ 28.6 GAINES CYCLE 1 (PUPPY) 14 OZ 208.9 KALKAN CHOPPED MEATY COMBO 14 OZ 129.7 KEN-L-RATION CHICKEN, BEEF, LIVER DINNER 33.9 KEN-L-RATION CHICKEN DINNER 30.2 RECIPE HEARTY MEAT DINNER 14 OZ 95.5 VETS-BEEF FLAVORED 15 OZ 62.5 ** SAMPLE TYPE: DRY CAT FOOD KALKAN CRAVE 18 OZ 135.7 CARNATION FRISKIES OCEAN FISH FLAVOR 168.6 STARKIST 9 LIVES CRUNCHY MEALS REAL TUNA & EGG 114.0 IAMS CAT FOOD 26 OZ 196.9 PURINA CAT CHOW 22 OZ 109.1 PURINA KITTEN CHOW 18 OZ 121.4 PURINA MEOW MIX 18 OZ 61.2 PURINA TENDER VITTLES MOIST CHICKEN DINNER 127.8 PURINA THRIVE 18 OZ 95.2 PURINA SPECIAL DINNERS SEA NIP DINNER 18 OZ 188.2 ** SAMPLE TYPE: CANNED CAT FOOD STARKIST AMORE TURKEY & GIBLET DINNER 3 OZ 94.0 STARKIST AMORE POACHED SALMON DINNER 3 OZ 101.2 CARNATION FRISKIES BUFFET TURKEY & GIBLET 6 OZ 80.0 CARNATION FRISKIES BUFFET SEAFOOD SUPPER 6 OZ 180.5 CARNATION FANCY FEAST BEEF & LIVER GOURMET 3 OZ 364.6 CARNATION FANCY FEAST FANCY SEAFOOD FEAST 3 OZ 115.4 KALKAN TENDER TURKEY DINNER 6 OZ 142.0 STARKIST 9 LIVES LIVER & CHICKEN DINNER 6 OZ 64.5 STARKIST 9 LIVES OCEAN WHITEFISH DINNER 6 OZ 134.3 PURINA 100 TUNA 6 OZ 294.3 PURINA BEEF & LIVER DINNER 6 OZ 595.6 __________________________________________________________________________